JPH104475A - Image scanner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the image scanner which is made small and in which power consumption is reduced by making a drive source small and saving the power consumption of the drive source by decreasing or eliminating a load at an acceleration region so as to raise the scanner at a high speed in a short time. SOLUTION: In this mirror scan type image scanner, mirror moving bodies 23, 24 are arranged along a rail 2 movably, the bodies 23, 24 are accelerated from a stop state till a scanning start speed in an acceleration region, nd scanned in a scan region after that, vibration of a mirror provided to the mirror moving bodies 23, 24 is eliminated by acting an suction force between the mirror moving bodies 23, 24 and the rail 2 in the scanning region so as to prevent a fogged and deformed image. In this case, the suction force between the mirror moving bodies 23, 24 and the rail 2 is smaller in the acceleration region than that in the scanning region.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image scanner, and more particularly, to miniaturization and power saving of a driving source used for a mirror scan, thereby reducing overall size and power consumption.
And an image scanner with low cost.

[0002]

2. Description of the Related Art Generally, in a copying machine, a facsimile, and an image input device of a personal computer,
An image scanner using a CCD line sensor is configured as shown in FIGS.

That is, a pair of rails 22, 22 for supporting a mirror in the operation direction are provided on opposing inner surfaces of a frame body 21, which is open up and down, and these rails 22, 22 are provided.
A first mirror moving body 23 and a second mirror moving body 24 are provided so as to extend between them. The first mirror moving body 23
Is composed of a first mirror unit 25 and a machine base 26, and
The second mirror moving body 24 includes a second mirror unit 27 and a machine base 28.

[0004] Reference numeral 44 denotes a leg provided on the lower surface of the machine base 26 and in contact with the rails 22, 22. Reference numeral 45 denotes a lamp provided inside the first mirror 25.

The first mirror portion 25 has an opening 29 formed on the upper surface thereof in a direction orthogonal to the rails 22, 22, and an opening on the side surface on the second mirror moving body 24 side. A first mirror 30 is provided for reflecting light rays from the opening 29 of the first mirror 30 to the second mirror moving body 24 side. Further, the second mirror portion 27 of the second mirror moving body 24 has an open side surface on the first mirror moving body 23 side,
A second mirror 31 that reflects the light beam received from the first mirror 30 and a third mirror 32 that receives and reflects the light beam from the second mirror 31 are provided therein. Also, 3
Reference numeral 3 denotes a lens barrel provided with a lens for receiving the reflected light of the third mirror 32 and a CCD line sensor.

[0006] Further, the frame members 21 on both ends of the rails 22, 22 are provided with shafts 3 that are orthogonal to the rails 22, 22.
4 and 35 are installed respectively, and one shaft 3
4 extends outside the frame body 21 to form a flywheel 36.
Is installed. A drive transmission pulley 37 is provided on a portion of the shaft 34 inside the frame 21, and is provided between the shaft 34 and a drive shaft of a stepping motor 38 which is a drive source mounted outside the frame 21. Is provided with a timing belt 39.

The shafts 34 and 35 are provided with pulleys 40a, 40b, 41a and 41b for the first mirror moving body 23 and the second mirror moving body 24, respectively, and one end thereof is provided in the frame 21. Is fixed to the pulleys 40 for the first mirror moving body 23 and the second mirror moving body 24 provided on both shafts 34 and 35.
a, 40b, 41a, 41b, the machine base 26 of the first mirror moving body 23, and the machine base 28 of the second mirror moving body 24, and the other end is fixed to the frame 21.

As described above, when the stepping motor 38 is driven, the first mirror movable body 23 and the second mirror movable body 24 have a predetermined relationship with each other when the stepping motor 38 is driven.
It moves along 2,22.

In the above-mentioned mirror type scanner, accurate position control and speed control can be performed by simple control. Therefore, a stepping motor is generally used as a drive source for driving mirror scan. is there.

However, since the stepping motor rotates by a predetermined angle for each drive signal, it gives a vibration to the mirror, and this vibration has a problem that the image is blurred and the image is deformed.

In order to solve such a problem, as described above, one end of one shaft 34 is extended to the outside of the frame 21 and a flywheel 36 is attached to smooth the rotation of the stepping motor 38. 7, the machine base 2 constituting the first mirror moving body 23 as shown in FIGS.
A magnet 43 is provided on the lower surface of 6 and a friction force is increased by applying a suction force between the magnet 43 and the rail 22, and a means for absorbing vibration by the friction force or a rotation speed region where vibration of the stepping motor is small is used. Means are employed.

Further, in the above means, as shown in FIGS. 7 and 8, a magnet 43 is provided on the lower surface of the machine base 26 constituting the first mirror moving body 23 to apply an attractive force to the rail 22. In the means for increasing the frictional force and absorbing the vibration by the frictional force, the following problems occur.

The operation of the image scanner includes a scan operation for taking in an image and a return operation for returning the mirror to the scan start position. The scanning operation has an acceleration region that accelerates from a stop state and reaches a predetermined speed, and a scan region where scanning is started.In the acceleration region where the mirror is being accelerated, a load due to acceleration is applied. The friction load increased by the suction force becomes a problem. That is, the load of the drive source always increases due to the frictional force of the magnet, and in the acceleration region where the load is accelerated to the scanning speed, a load due to acceleration is applied.
The load of the frictional force by the magnet becomes a problem.

For this purpose, a motor with a high torque output is used, or a flywheel is reduced in order to reduce the load during acceleration. However, when a motor with a high torque output is used, the size of the motor increases and the consumption increases. When the current increases and the flywheel is made smaller, the effect of the flywheel is reduced and the vibration is increased.

According to the present invention, the load of the frictional force is made smaller in the acceleration region than in the scan region in the acceleration region without increasing the size of the drive source for high torque output or the downsizing of the flywheel. It is an object of the present invention to provide an image scanner which can be started up and can absorb vibration in a scan area.

[0016]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention moves a mirror moving body along a rail by a driving source to perform a scanning operation and a return operation.
During the scanning operation, an acceleration area that accelerates from the stop state,
In an image scanner that moves between a scan area for reading an image and a scan area, a suction force is applied between the mirror moving body and the rail, and the suction area is configured such that the acceleration area is smaller in the acceleration area than in the scan area. Have.

A notch is formed in a portion of the rail corresponding to the acceleration region, and a magnet is provided in a portion of the mirror moving body facing the rail, and the magnet faces the notch. At the time, the suction force between the mirror moving body and the rail is eliminated, whereby the suction force acting between the mirror moving body and the rail is smaller in the acceleration area than in the scan area, An electromagnet is disposed on the mirror moving body, the electromagnet is opposed to the rail, and a detection member is disposed.
The energization is released only when facing the rail corresponding to the acceleration area, whereby the suction force acting between the mirror moving body and the rail becomes smaller in the acceleration area than in the scan area. Have.

Further, a magnet is provided on the mirror moving body, and the magnet is opposed to the rail, and a member for reducing the attractive force of the magnet is provided at a portion of the rail corresponding to the acceleration region. Thereby, the suction force acting between the mirror moving body and the rail is configured to be smaller in the acceleration region than in the scan region.

[0019]

According to the present invention, as described above, in the acceleration region from the stop to the start of the scanning operation, a large suction force does not act, so that it is possible to quickly start up in a short time. In the scan area, a large suction force acts, so that the mirror moving body vibrates, so that blurring and deformation of the image can be reliably prevented.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An image scanner according to the present invention shown in the drawings will be described below. 1 to 4 show an image scanner according to the present invention. FIG. 1 is an overall schematic view of the image scanner, FIG. 2 is a schematic view showing a state where a part of the image scanner is removed, and FIG. FIG. 4 is a schematic plan view showing an acceleration region required for acceleration until the scanning operation is started, and FIG. 4 is a schematic front view of FIG.

In the overall schematic view of the image scanner, the same members as those of the conventional image scanner are denoted by the same reference numerals, and description thereof is omitted.

In the image scanner according to the present invention, the rails 2 and 2, which are rails provided to face the inner surface of the frame 21, perform the scanning operation from the position where the first mirror moving body 23 is stopped. A portion between the starting positions is cut out to form a cutout 3.

That is, the magnet 43 provided on the lower surface of the machine base 26 of the first mirror moving body 23 is opposed to the notch 3, and the leg 44 provided on the lower surface of the machine base 26 is The upper surfaces of the rails 2, 2 facing the notch 3 without being located in the notch 3 are brought into contact with each other.

Therefore, the portion where the notch 3 is provided is the acceleration area a of the first mirror moving body 23,
It is outside the scan area.

In the case of the above configuration, when the driving source 38 is started while the first mirror moving body 23 and the second mirror moving body 24 are in a standby state, that is, in a stopped state, a stepping motor which is a driving source. The driving force of 38 is transmitted to the shaft 34 via the timing belt 39.

On the other hand, a pulley 40 provided on the shaft 34
a, 40b, pulleys 41a, 41b provided on another shaft 35 provided on the frame 21, and the first mirror moving body 23
Since the wires 42 are laid between the machine base 26 of the second mirror moving body 24 and the machine base 28 of the second mirror moving body 24, the first mirror
The mirror moving body 23 and the second mirror moving body 24 start a scanning operation while maintaining a predetermined relationship.

When accelerating in the acceleration area and reaching the effective scanning area, the magnet 4 provided on the lower surface of the machine base 26
3 does not face the notch 3 of the rail 2 but faces the upper surface of the rail 2. Therefore, a suction force acts between the rail 2 and the rail 2 to increase the frictional force. The vibration generated when the mirror moving body 23 performs the scanning operation in the scanning area can be absorbed.

Therefore, when the scanning operation is started, the scanning is accelerated from the stop state, and the scanning is started after reaching the predetermined speed. However, while the first mirror moving body 23 is accelerating in the acceleration area a, the notch 3 Due to the presence, only the load due to acceleration is applied, and the frictional load due to the attractive force of the magnet 43 does not matter at all. Moreover, since the acceleration area a of the first mirror moving body 23 is usually outside the effective scan area as described above, there is no problem even if there is no countermeasure against vibration by the magnet 43.

In the above embodiment, the permanent magnet 4
3 was used, but an electromagnet may be used. In this case, a frictional force is generated between the rail and the rail by energizing and energizing the effective scan area. The energization may be stopped to eliminate the suction force, and this timing can be set by providing a sensor or the like.

Further, even when the electromagnet is always energized, it is possible to generate a suction force only in the effective scan area by providing the notch, and it is possible to correspond to the notch without providing the notch. This may be a case in which a member capable of blocking or weakening the suction force is provided in the acceleration region a.

[0031]

According to the present invention, since the frictional force which hinders acceleration in the acceleration region can be made smaller than that in the scan region in the acceleration region, the present invention provides a drive source having a small output torque. However, in the effective scan area, the vibration of the mirror can be prevented by the frictional force, and the blurring of the image and the deformation of the image can be prevented. Therefore, it is possible to reduce the load during acceleration in the acceleration region up to the scan region and to start up to a high speed in a short time without enlarging the drive source and the flywheel in size. In addition, since the drive source can be downsized, the overall size of the image scanner can be reduced and current consumption can be reduced. In addition, since there is no need to reduce the size of the flywheel, mirror vibration can be effectively prevented. have.

Further, when a notch is provided in the rail to eliminate the suction force in the acceleration region, the load on the acceleration due to the suction force is eliminated, so that the acceleration efficiency can be increased.

[Brief description of the drawings]

FIG. 1 is an overall schematic diagram of an image scanner according to the present invention.

FIG. 2 is a schematic view showing a state in which a part of FIG. 1 is removed.

FIG. 3 is a schematic diagram showing a relationship between a machine base and a rail constituting a mirror moving body according to the present invention.

FIG. 4 is a schematic front view of what is shown in FIG.

FIG. 5 is an overall schematic diagram of an image scanner according to the present invention.

FIG. 6 is a schematic view showing a state in which a part of FIG. 5 is removed.

FIG. 7 is a schematic diagram showing a relationship between a machine base and a rail constituting a mirror moving body according to the present invention.

FIG. 8 is a schematic front view of what is shown in FIG.

[Explanation of symbols]

 2, 22 ... rail 3 ... notch 21 ... frame 23 ... first mirror moving body 24 ... second mirror moving body 25 ... first mirror section 26, 28 ... machine stand 27 ... 2 mirror section 29 opening section 30 first mirror 31 second mirror 32 third mirror 33 lens barrel section 34, 35 shaft 36 flywheel 37 pulley 38 … Stepping motor 39… Tumming belt 40a, 40b, 41a, 41b… Pulley 42… Wire 43… Magnet 44… Leg 45… Ramp a… Acceleration area

Claims (4)

[Claims] An image scanner that moves a mirror moving body along a rail by a driving source to perform a scanning operation and a return operation, and moves a scanning region for accelerating from a stopped state and a scanning region for reading an image during a scanning operation. The image scanner according to claim 1, wherein a suction force is applied between the mirror moving body and the rail, and the suction force is smaller in the acceleration area than in the scan area. 2. A notch is formed in a portion of the rail corresponding to the acceleration region, and a magnet is provided in a portion of the mirror moving body facing the rail, and the magnet faces the notch. 2. The apparatus according to claim 1, wherein the suction force between the mirror moving body and the rail is eliminated during the time, whereby the suction force acting between the mirror moving body and the rail is smaller in the acceleration area than in the scan area. Image scanner as described. 3. An electromagnet is disposed on the mirror moving body, the electromagnet is opposed to a rail, and a detecting member is further disposed. The detecting member is arranged so that the electromagnet faces a rail corresponding to an acceleration region. 2. The image scanner according to claim 1, wherein the energization is released only when the operation is being performed, whereby the suction force acting between the mirror moving body and the rail is smaller in the acceleration area than in the scan area. 4. A magnet is provided on the mirror moving body, and the magnet is opposed to a rail, and a member for reducing the attraction force of the magnet is provided at a portion of the rail corresponding to the acceleration region. 2. The image scanner according to claim 1, wherein the suction force acting between the mirror moving body and the rail is smaller in the acceleration area than in the scan area.